Switch-operating mechanism



Jan. 9, 1923.

v wJK RANKIN, SwsrcH DPERAUNG MEcHANlsM.

. Inverwlor: William K-Rmim, b Mw Patented Jan. 9, 1923.

UNITED STATES WILLIAM K. RANKIN, v0]? SCHENECTADY.

NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIC COMPANY, A COBPORATON OF YORK.

SWITCH-OPERATING MECHANISM.

Appncaaon lmeri september 7, i921. semi No. 499,111.

i l To all 'u1/rom. 1t may co'uccm:

Be 1t .known that I, lViLLiAM K.,Ra1\fmi\'.

a. `,citizen of. ,the United States, residing at.

Schenectady,i county of Schenectady, State ,of New. York have.;.inventeihcertain new and useful;IniprovementsinlSwitch-U )eratiugllfechanisms, ofr.which tlielfollowmg is aspecieation. ,4 i. a j, M yinvention relates to electrical Vsviitches and particularly to those switches of a high potential type wherein the movable contacts are. enclosed in a vessel and are operated by means external thereto. In many theoil switches in use at the present time movement of the contacts is effected by means of rods or similar members which extendwthrough the top or walls of the switch vessel and the arangement is often such that linthe openingr of the switch the operatingrml moves toward the interior of the (easel. In thc case of switches carrying considerable current the opening of the circuit causes a high pressure toghe "developed within the vessel by 'reason of the vaporization and disassociation rof the oil or other liquid in which thc contacts are immersed and this pressure acting upon the' operating means whichpasses through thewall of the vessel causes the same to move in a direction'to close the switch. If the switch has been tripped open b v reason of a short circuit. its

automatic reclosing may cause a reestablishmcnt of the short circuit, with the result that the system may be considerably damaged. In high power switches wherein the expulsion of the arc gases from the vessel is retarded and in which there is consequent-ly developed very high pressure the provision of some means to prevent the reclosing of the switch in the manner described is a matter of urgent necessity.

One of the objects of the present invention is to provide means of this character which shall prevent the ieclosing of the switch in the manner described not only after the switch has been fully opened but during all stac'es of the opening operation.

ther objects and advantages will appeal' from the following description taken in connection with the accompanyingr drawing wherein Fig. 1 represents a vertical section partly broken away ot' a switch and operating means embodying my invention, and Fig. 2 is a similar view showing ay modification. Referring to Fig. 1. 10 and 11 reprefsentrespectively the stationar)7 and movable .switchcontacts aridll a vessel adapted to containoil or similarfinsulating fluid in wh'iclrthe contacts .'10 and 11 are immersed. In the particular iforin of switch illustrated. the .vess'elis vco nstrllrlgted to withstand considerable internal pressure and all joints are .,inadetilfhtito prevenltoil from being thrown ATout of t le4 vessel'when the'switcli interrupts a lrieavy shortcircu-it In the type of switch hereushown there are two stationair)r contacts Aand two movable contacts, the latter being carried by an'winsulating rod 14. llod 14 is V formed yat itstupper end with an enlarged portion or head lwhicli is adapted to more within an operating member 1G. This mem ber may. if desired. be tubular in form and is prcferabl provided at its lower end with an inturne( flange 17 arranged to prevent the withdrawal (if the head 15. )lemhcr lo isfpivotallv secured lat 19 to the lcvcr 2() to which the usual operating means employed in switchesof t'histype is connected. 'l`hc head 15 is fortned with a slot :2l at thc bottom of which are two incliucd faces 2L). Depending from the'pivotal connection 151 are two pawls 23 arranged to more outwardly in opposite directions ilito engagement with teeth 24 formed 4upon the stationarwuprights Q5. slots 26 being `forined in the lilcinber 16 through which the pawls are adapted to move toward this engaging position.

Tn operation the switch is closed bv rais- .ing the switch-operating lercr which through the member 16 and rod 1-1 lifts thc contacts 11 into engagement with the stationary contacts 10. In order to open t-he switch thc 'operating lever is released and the rod 14 falls carrying with it contacts 11. lf upon the separation of the contacts sufficient pressure is developed in the vessel 12 to force `the rodY 14 upwardly. the faces :Ztl on the pawls will engage the faces of the pawls 2. with the result thatl thc lower ends of the pawls will be forced outwardly through thc slots 26 and into engagement with the teeth Q4. This will prevent any further upward movement of the contacts l1. The arc. if it has not been extinguished at thc time this takes place. will subsequently be extinguished due to an increase in pressure within the vessel 12, or if desired other means may be employed to insure thc extinguish in(T of the arc.-

tit is to be noted that it wil be impossible formed witlra cupzfshilied portion- Mlu'ithin which' is adaptedltfbe seated 4the-'lower shoes 43' which are adapted! to be.'I forced upwardly against friction surfaces-i 50 foi-mcd on tlie` i ip.l'iglrts 25. "If desiredto prevent any slippingcaused h v oil which ma)7 he thrown onto the friction surfaces 'v5 Jill, these surfaces lnav be' considerably ronghcned. livotally secured at their inner4 ends to the rod-ll 'are links 44 which have formed at their outer ends slots 45 wluch arc adapted to'recelve. )Ins 4G secured to the links- 42. Stops 4T formed intherod 14 sci-ve to limit tl|e` \p\\"ard movement of the links 42. :l

ln operation the switchisl closedhv' raising the rudfll which Ioperating through the links '1l raisesl thelv'rodIll and the movable contacts. llnriugqthis operation the shoes lll move slightly away from ,the surface 50, thc links heilig held against rotation hyengagcmeut. with stops 4T. 40 selves are prevented from rotating ontwardlr toward the friction surfaces 50 hy lugs fil formed thereon which engage the sides of the 4links 42. During the. opening of the switch the rods 41 and 1-1 fall and the 45 hrakc shoes ride over thesurfaccs 50. In case, however. the. pressure within the vessel is such thatv the rod 14 starts to rise, the brake shot-s are forced outwardly against the surfaces :'10 and au)r appreciable upward Inovenlcut is prevented.

'hatl claim-as new and desire to secure liv Lettcls Patent of the United States, is,-

il. switch of the type which comprises a vessel. and cooperating contacts separahle within said vessel to draw au arc. aud whereits consequent i rz- The shoes them-v in pressure is crcatedat the separation of Said contacts which tends to force said contacts together. cha ractcrizcd hv thc fact that lncans is p|'o\`ided which will prevent the ,movement of said contacts under tht` in Ilucncc ol' said pressure to closed position from anvposition occupied thcrchy during the opening operation.

9:5. switch of the type which comprises a vessel adaptcd toc'ontain an insulating tiuid. and mpi-rating contacts within said 'vesseladzlptedto be inmifcrsed in said Huid. v'and 'wherein press-ure is created at the scpariition'iof said/contacts whichtends to force4 the contacts together, characterized hy the 'factftlaftlxere'is means operable to prevent' the reversal inthe movement ofthe contacts because of such pressure fronranv .position cwcuil'ied b v the salue during the Vopening of the switch.

. ..\n 'electric'switch comprisingr a vessel contacts separable within said vessel to draw an arc, operating means for said contacts including a connection extending into fsaid vessel, und movahle toward the interior of said vessel to` separate said contacts. and ineans operable to prevent the pres sure within said vessel from reversing the motion 'of said contacts said means hciug adapted to operate at all stages of thc o penin'g operation.

4, In u switch of the type which coinprise'sa .v'essel, and cooperating contacts sepa'rahlewithin said vessel to draw au arc and wherein pressure is created at thc scpA aration of said contacts which tends to force said contacts together. characterized by the fact that means is provided which is operahle hy said pressure to prevent the reclosure ofsaid contacts.

n electric switch comprising a vessel, contacts separable within said vessel to form an are1 operating means for said contacts including a connection extending into said vessel and movahle toward the interior of said vessel to sepamte said contacts, said operating means heing formed with a lost motion connection and means responsive to the lost motion of said connection caused h v the pressure created within said vessel at the selvmrat-ion of said contacts to prevent their reclosure..

In witness whereof, I have hereunto set in v hand this 6th da)` of Se )temher` 1921.

lVlldllAM RANKIN. 

